The invention relates generally to the field of disk drive sliders, and in particular to disk drive sliders having read and/or write heads which are used in configuration with flexible recording media. In a preferable aspect, the invention provides for a pair of opposing sliders between which a flexible media is rotated at relatively high speeds.
Current data storage systems employ a wide variety of media to store digital information. One particular recording medium which is of interest is a flexible disk. Traditionally, disk drive systems which were adapted to receive flexible disks employed the use of a read/write head which is normally in contact with the flexible disk. With such systems, low rotational speed of the disk (such as 360 rpm) serves to minimize wear to the contacting surfaces.
In order to increase the amount of data that can be stored on a flexible disk, some have implemented the use of dual sided flexible disk recording devices which utilize recording heads that are generally directly opposed. Usually, one magnetic head slider is fixed normal to the plane of the disk. The opposite slider is typically gimbal-mounted to a support arm and is lightly loaded toward the disk and the fixed-head slider. The gimbal typically allows its slider to translate toward and away from the disk and allows two degrees-of-freedom of slider rotation (called pitch and roll) with respect to the plane of the disk. The typical gimbal thus provides three degrees-of-freedom of motion to the attached slider. At low rotational speeds, a nominally contact condition occurs between slider and disk on both sides of the disk. Due to the low speed, the amount of head and disk wear is controlled to an acceptable level.
Instead of utilizing head/disk contact to ensure close proximity to the flexible disk as is typical in low-speed devices, some have proposed utilizing a head/disk interface which operates without surface contact between the head slider and flexible disk at elevated rotational speeds. Use of such a non-contact head/disk interface allows for increased data transfer rates as well as preventing wear to the disk. Further, by providing a dual head arrangement, increased storage capacity may be provided by allowing for the information to be recorded on both sides of the flexible disk.
U.S. Pat. No. 4,974,106 (the '106 patent), the disclosure of which is herein incorporated by reference, describes an exemplary arrangement for dual-sided recording on a flexible disk which is rotated at relatively high rotational speeds. The '106 patent describes a pair of opposing sliders, each slider having a hydrodynamic pressure pad (HPP) and a longitudinal rail. The two sliders are arranged such that the HPP of each slider will oppose the longitudinal rail of the other slider. Further, each of the longitudinal rails is provided with a pair of longitudinal slots having a uniform width. With this arrangement, pressurized films are developed over both the slotted head longitudinal rail and the HPP, which defines the flying height. Such a film is greater on the side of the HPP and lesser on the side of the slotted longitudinal rail due to the pressurized air flow being bled off through the slots. Further, the pressure force on both sides of the disk is generally equalized with the result being that the air film thickness adjacent to the HPP pushes the disk towards the slotted rail. In this way, the arrangement in the '106 patent allows for a nominally non-contact, low-clearance flying height to allow a flexible media disk drive to operate at about the speed and capacity of a hard media disk drive.
Although the configuration described in the '106 patent has proved to be generally successful, it will be desirable to provide various improvements. For example, when including a read and/or write transducer, such as a high-density transducer, on the rail face near the trailing edge, it is desirable to reduce the fly height value in the immediate vicinity of the high density magnetic transducer while also providing controlled fly height values elsewhere on the slider in order to minimize exposure to contact and wear over the head/disk interface. As another example, it would be desirable to more carefully control the pitch angle of the slider since the pitch angle contributes to the overall stability and reliability of the air bearing film which separates the slider and disk.
In some cases, it will be desirable to provide the longitudinal rail with a high density magnetic transducer in the vicinity of the trailing edge and a low density magnetic transducer which is longitudinally spaced apart from the high density magnetic transducer. With such an arrangement, it will be desirable to be able to control the flying height of the longitudinal rail in both the vicinity of the high density magnetic transducer and in the vicinity of the low density transducer. In this way, the flying height for both transducers may be optimized. In some cases, it would be desirable to provide a slider arrangement which may operate at low fly height values for applications in which a high density magnetic head is deposited at the slider trailing edge. For example, it would be desirable to provide such a configuration which could accommodate thin-film-inductive (TFI) and magnetoresistive (MR) types whose deposit on the slider trailing edge involves techniques common to the semiconductor industry.